this will work:

with oHeader
*oPageNumber = oHeader.PageNumbers.Add()
*oPageNumber.Alignment = wdAlignPageNumberRight
oHeaderRange = oHeader.Range()
with oHeaderRange

.Font.Name = "Arial"
.Font.Size = 20
.Font.Bold = 1
.ParagraphFormat.Alignment = wdAlignParagraphCenter
.InsertAfter("TOP ROW IN HEADER")

.Collapse(wdCollapseEnd)
.end=oheaderrange.end + 1
.InsertAfter(CHR(13))
.Font.Size = 10
.InsertAfter("Middle Row in Header")

.Collapse(wdCollapseEnd)
.end=oheaderrange.end + 1
.InsertAfter(Chr(13))
.Font.Size = 8
.InsertAfter(dtoc(date()))
endwith
endwith